Mitsubishi Colt Battery Problems

my car burnt the computer box and i bought a second hand which worked on the same car as mine and also replaced the crank censor and now it doesnt start but if you connect the pump soloned direct to the battery it starts with very high revs...

tryed starting thismorning and its very cold but car wont start

after driving come back to drive starts up but when you put into or revers wont move forward or back words after rebooted it seams fine but there must be a problem with it

Was driving about to pull in, and a yellow light flashed and turned off the engine, then tried to restart, but no power to anything, all electrics gone.

Green screen display is stuck on and does not go off when ignition is off Battery is getting drained within a day , possibly because of the above issue.

Removed battery to clean and tighten connectors car is now in immobilizerd mode fires up but won't start keys have been re synced not the problem autonator fuel pump checked all fine